1. Field of the Invention
The present invention relates to a press-action device. More particularly, the present invention relates to an elongated press-action device, such as a writing instrument, a toy, or an ornament/accessory attached to a key-chain, a necklace, a cell phone, etc.
2. Description of the Related Art
A window pen is one type of press pen which has been developed for a very long time. Generally, when a user pushes a button of the window pen, a pattern (such as a text pattern or a graphical pattern) displayed on the window of a holding barrel is changed accordingly. The principle of the window pen is that once the button of the pen is pressed, the cartridge of the window pen rotates slightly. Therefore, a rotation barrel printed with a plurality of patterns (such as text patterns or graphical patterns) is mounted on the cartridge such that when the pen cap is pressed, the rotation barrel is driven to rotate and thus causes the plurality of patterns printed on the rotation barrel to be displayed in turn in a window. Please refer to U.S. Pat. Nos. 2,896,348, 2,971,283, 3,343,293, 6,386,780 and 6,742,953 for more details of the structure of the window pen.
However, in known prior arts, the plurality of patterns are always displayed in turn. After a user is familiar with the sequence of the patterns, the user can easily predict the content of the next pattern to be displayed. As a result, the traditional window pen becomes boring very soon. Therefore, if the plurality of patterns can be randomly displayed in the window, the user will feel much more interested and amused.
Further, a conventional window pen only has one rotation barrel. Therefore, the window can display only one certain pattern of the rotation barrel at one time. If the window pen has a plurality of rotation barrels, such as three rotation barrels, when the pen cap is pressed, these rotation barrels can independently rotate to randomly display different patterns, thus increasing the entertainment value. The most common three-barrel rotation mechanism is a slot machine. Please refer to U.S. Pat. Nos. 3,565,441, 4,002,335, 4,037,845, 4,097,048, 4,261,571, 4,492,379, 4,666,159, and 5,054,782 for more details of the structure of a slot machine. However, in the abovementioned prior art patents, the driving mechanism for the rotation barrel is basically installed in one side of a rotation barrel. It is very difficult to implement the existing mechanism of the slot machine in a window pen, since the interior space of the window pen is very narrow. Further, in order to contain the driving mechanism, the diameter of the rotation barrel has to be half of that of the holding barrel, but such a design would allow only a very small pattern to be printed on the rotation barrel. In the technical field of a conventional window pen, the concept of a plurality of freely-rotating rotation barrels has never been disclosed. Even if someone were to come up with the idea of combining a plurality of rotation barrels with a window pen, he/she would still need to solve the problem of the very small interior space of the holding barrel.